The present invention relates to a driving apparatus and, more particularly, to an arm driving apparatus for a vertical multi-articulated robot.
Multi-articulated robots have been proposed and a number of arm driving apparatus have also been proposed wherein the first and second arms as well as the associated wrist and/or fingers are provided with search elements being naturally subjected to gravitational forces thereby resulting in the necessity of providing a brake such as, for example, an electromagnetic brake, for stopping the action of the multi-articulated robot. Furthermore, in the proposed robots, mounting of a pressure sensor for detecting forces applied to the fingers of the robot is extremely difficult since there is not suitable installation space for the pressure sensor.
An object of the present invention is to prevent the arms of a vertical multi-articulated robot, for example, when this robot is to be stopped, from being shifted from a target stop (or vertical) position by the weight of a load.
Another object of the present invention is to detect that an extraordinary load is applied to the arms of the robot.
In order to achieve the above-specified objects, in accordance with the present invention, a worm gear and a worm wheel are used in an arm driving apparatus, with an extraordinary load being detected by pressure sensors attached to the opposite ends of a worm gear shaft.